NFL Quarterbacks,Why do all NFL quarterbacks have a green dot on the back of their helmets?

It signals which player is receiving audio signals for the plays. Only one player per team is allowed to be on the field with one of these.

The symbol formerly known as Burnt Sienna made the NFL put it on the QB's helmets because he loves to answer this question so much.

Its so Joey harrington can get yelled at by his coach more

its the helmet that has a connection with the coaching staff so they can be told the play without going to the sideline.

It is for environmental awareness, thought up by Al Gore, to remind us all of global warming. If median temperatures rise by an average of .5% in the next year, the dots will be red next year. If we have a cooling average of .5%, they will be blue.

what is wrong with all these people asking the same question over and over. this is getting messed up. everyday there is the same question atleast 10 times.

So the DB's can get a good run up at the right player

so they can pick their helmets out of a line up

I swear you are asking this as a joke...

are you that lazy, where you cannot find the other 45,763 questions just like this?

They have 666 on their foreheads.

That's the mark that they have a microphone in their helmet.